I have come across an issue that has confused me a lot.
I am working on a login screen using PHP and MySQL. I manage to validate the username and password against an existing user in the database and after this, I initiate a session, and set the session variable username to the username provided in the login screen.
$username = html($_POST['username']);
$password = html($_POST['password']);
$result = $pdo->prepare('SELECT * FROM users WHERE username = :username AND password = :password');
$result->bindValue(':username', $username);
$result->bindValue(':password', $password);
$result->execute();
foreach($result as $user)
{
$count = $count + 1;
}
if ($count == 1)
{
session_start();
$_SESSION['username'] = $username;
` //if I do an echo $_SESSION['username'] it displays the correct user
header('Location: .');
exit();`
}
However when it transfers me to the index.php page the $_SESSION['username'] variable has disappeared and I do not understand why. This is the code I use in index.php to check for the username:
<p>View all tasks</p>
<p>Add your own task</p>
<p>Welcome, <?php echo $_SESSION['username']; ?></p>
however I get the following error: Notice: Undefined variable: _SESSION in C:\xampp\htdocs\abcabcabc\index.php on line 16
All advice will be greatly appreciated guys
Add sesssion_start() to all of your scripts that use the session
You must use session_start(); at the beginning of index.php file.
The first 2 answers are correct. You must start session on each page. I usually just put it in a file that is "included" in every page already (like a header file) so I don't have to think about it.
Related
I am trying in my PHP to make it to where if the Account database value matches 0 or 1 or 2 or 3 then it makes the login go to a certain page but so far it doesn't log me in and it doesn't take me to the page. Before I had a log in page but it sent it to a universally restricted page, but what I want is depending on what the User signed up for then he gets put this value(which I have already implemented) that if this page were to work than it would send him to one of four restricted sites upon login. What I can't get is the value to get pulled and used to send him upon login to the specific page.I am using Mysqli. Here is the code:
<?php require 'connections/connections.php'; ?>
<?php
if(isset($_POST['Login'])){
$Username = $_POST['Username'];
$Password = $_POST['Password'];
$result = $con->query("select * from user where Username='$Username'
AND Password='$Password'");
$row = $result->fetch_array(MYSQLI_BOTH);
$AccountPerm = $con->query("SELECT * FROM `user` WHERE Account =
?");
session_start();
$AccountPerm = $_SESSION['Account'];
if($AccountPerm == 0){
header("Location: account.php");
}
if($AccountPerm == 1){
header("Location: Account1.php");
}
if($AccountPerm == 2){
header("Location: Account2.php");
}
if($AccountPerm == 3){
header("Location: Account3.php");
}
}
?>
so far it doesn't log me in
Just to be sure, your Account.php, Account1.php, Accout2.php and Account3.php rely on $_SESSION['Account'] right? (The code below assume so)
As for your problem with both login and redirecting you forget a line :
$_SESSION['Account'] = $row['Account'];
Also, I removed
$AccountPerm = $con->query("SELECT * FROM `user` WHERE Account =
?");
You code should look like :
<?php require 'connections/connections.php'; // NOTE: I don't close the php tag here ! See the "session_start()" point in the "Reviews" section below
if(isset($_POST['Login'])){
$Username = $_POST['Username'];
$Password = $_POST['Password'];
// TODO: Sanitize $Username and $Password against SQL injection (More in the "Reviews" section)
$result = $con->query("select * from user where Username='$Username'
AND Password='$Password'");
// TODO: Check if $result return NULL, if so the database couldn't execute your query and you must not continue to execute the code below.
$row = $result->fetch_array(MYSQLI_BOTH);
// TODO: Check if $row is NULL, if so the username/password doesn't match any row and you must not execute code below. (You should "logout" the user when user visit login.php, see the "Login pages" point in the "Reviews" section below)
session_start();
$_SESSION['Account'] = $row['Account']; // What you forgot to do
$AccountPerm = $_SESSION['Account'];
if($AccountPerm == 0){
header("Location: account.php");
}
if($AccountPerm == 1){
header("Location: Account1.php");
}
if($AccountPerm == 2){
header("Location: Account2.php");
}
if($AccountPerm == 3){
header("Location: Account3.php");
}
}
?>
Reviews
session_start()
Should be call at the top of your code. (It will probably end-up in a a shared file like connections.php that you will include in all of your file).
One reason is that session_start() won't work if you send ANY character to the user browser BEFORE calling session_start().
For exemple you close php tag after including connections.php, you may not know but you newline is actually text send to the browser !
To fix this you just have to not close your php tag, such as in
<?php require 'connections/connections.php'; ?>
if(isset($_POST['Login'])){
Login page
Make sure to logout (unset $_SESSION variables that you use to check if user is logged) the user in every case except if he enter the right username/password combinaison.
If the user is trying to login it may be a different user from the last time and we don't want him to be logged as somebody else if his username/password is wrong.
MySQL checks : You should always check what the MySQL function returned to you before using it ! (see the documentation !) Not doing so will throw php error/notification.
SQL injection : You must sanitize $Username/$Password before using them into your query.
Either you append the value with $con->real_escape_string() such as
$result = $con->query("SELECT * FROM user WHERE Account = '" . $con->real_escape_string($Username) . "' AND Password = '" . $con->real_escape_string($Password) ."')
or you use bind parameter, such as explained in this post (THIS IS THE RECOMMENDED WAY)
No multiple account pages
Your login page should redirect only to accout.php and within this page split the logic according with the $_SESSION['Account'] value.
Nothing stop you from including account1.php, account2.php, ... within account.php.
If you do so put your account1.php, account2.php, account3.php in a private folder that the user can't browse in.
(One of the method is to create a folder (such as includes) and put a file name .htaccess with Deny from all in it)
I know I can't use two session start codes in a same php page but for the sake of updating user account, I need the below code and I need to use session_start twice. One, to check if the user is not logged in, then redirect them and banned them from seeing the update info page and also the other session start has to be there so that my session variables could be set automatically in the update info page if the user is logged in.
anyways, I am getting this error can you guys please show me a work around way? if there's any?
thanks.
Notice: A session had already been started - ignoring session_start() in ....
<?php session_start();
if(isset($_SESSION['userid'])) {
} else {
header('Location: login.php');
}
?>
<?php
$user = $_SESSION['userid'];
$myquery = "SELECT * FROM our_users WHERE `userid`='$user'";
$result = mysqli_query($conn, $thequery);
$row = mysqli_fetch_array($result, MYSQLI_BOTH);
session_start(); /* Basically this right here gets ignored. */
$_SESSION["user_first_name"] = $row['fn'];
$_SESSION["user_last_name"] = $row['ln'];
$_SESSION["user_email"] = $row['em'];
$_SESSION["user_password"] = $row['pw'];
?>
I have created a user authentication system with necessary DB tables and php.
THe first time before I login (Before any SESSION is created) the redirect on every page works perfect (ie Redirects to the login page if not logged in).
But once I login with a user and then logout the same doesnt work. I think it might be a problem with not ending the SESSION (Sorry if am wrong)
Here are some pieces of the code in each Page
Login PHP
<?php
session_start();
$message="";
if(count($_POST)>0)
{
include('config.php');
echo $_POST['username'];
$result = mysql_query("SELECT * FROM members WHERE username='" . $_POST["username"] . "' and password = '". $_POST["password"]."'");
$row = mysql_fetch_array($result);
if(is_array($row))
{
$_SESSION["id"] = $row[ID];
$_SESSION["username"] = $row[username];
$_SESSION["password"] = $row[password];
$_SESSION["mname"] = $row[mname];
$_SESSION["fname"] = $row[fname];
date_default_timezone_set("Asia/Calcutta");
$lastlog=date("d/m/Y");
$logtime=date("h:i a");
$query = "UPDATE `members` SET `lastlogin`='$lastlog',`logintime`='$logtime' WHERE `ID`='$row[ID]'";
mysql_query($query);
$_SESSION['logged'] = TRUE;
}
else
{
echo "<SCRIPT>
alert('Wrong Username/Password or Awaiting Approval');
</SCRIPT>";
header("Location:login_failed.html");
}
}
if(isset($_SESSION["id"])) {
header("Location:member/myprofile.php");
}
?>
PHP code on every page
<?php
session_start();
include('config.php');
if(!$_SESSION['logged'])
{
header("Location: ../login.html");
exit;
} ?>
And Finally Logout
<?php
session_start();
unset($_SESSION["id"]);
unset($_SESSION["username"]);
unset($_SESSION["password"]);
unset($_SESSION["mname"]);
unset($_SESSION["fname"]);
header("Location:../login.html");
?>
Is there any problem with my Code. Am i missing something? I couldn't get it right. Pls Help
Thanks guys got it solved..
Now can you tell me How I can redirect login.php to user home page(myprofile.php) in case the User is logged in (Session exists) - Like facebook,gmail etc
Instead of calling unset() on each session var, you can simply use session_destroy(), which will destroy all of the current session data.
session_start();
session_destroy();
header("Location:../login.html");
For complete destructive power, you might also want to kill the session cookie:
setcookie(session_name(), '', 1);
See this question for a more complete example of session logout.
You need to unset $_SESSION['logged']
Also you should reference keys in the $row variable with strings. Eg $row['username'];.
Turning on E_NOTICE level warnings with error_reporting will help you with this.
If you haven't already, reset the session login
unset($_SESSION['logged']);
Or just change it to false
$_SESSION['logged'] = false;
When you are directly hitting a page in address bar for the first time then its a new request which goes to the server and server checks for existing session as written in your code. But its not same when you are pressing back button after logout. In this case there is no request is going to the server instead the request is fetched from browser cache. If you want to disable this situation then you have to tell browser explicitly to not to store your page in cache memory. For more detail please go through this link
I need the login details in another page for retrieving the data from the database. Basically, I need to display the editable form with the details of the user logged in. I tried session_register() for storing the username in login.php page. But for some reason I am not able to display the username using $_SESSION[] in my edit.php page. I am doing this after the function session_start() as well.
I am new to php, so don't know whether I misunderstood session! Or is there any other way to pass the login details?
Thanks in advance
My code:
**Login.php**
<?php
$userName = $_POST['username'];
$password = $_POST['password'];
//Connect to the database
//query the database
if($rows==1)
{
session_start();
$_SESSION['user']=$userName;
header("location:edit_user.php");
}
else
{
echo 'Data Does Not Match <br /> Re-Enter UserName and Password';
}
?>
**In edit.php**
<?php
session_start();
if(!isset($_SESSION['user']))
{
header("location:login_form.php");
}
else
{
echo $_SESSION['user'];
}
?>
First of all make sure that you place session_start() at the very beginning of any script you use it in. There can be no output to the browser before you call session_start() and that includes spaces or new-lines before the opening <?php tag.
So:
<?php
session_start();
...
Second, make sure you terminate your script after a redirect, for example:
header("location:edit_user.php");
exit();
That makes sure that no code after the redirect gets executed, so sessions won't get unset or session variables changed by accident.
session_register() is a deprecated function. Just use $_SESSION["bar"] = "foo" to store something.
for future references, please post parts of your code when you are asking questions. It helps everyone to give you an answer in more specific cases.
<?php
session_start();
if(!isset($_SESSION['Foo']))
{
$_SESSION['Foo'] = "Bar";
}
?>
Source : http://php.net/manual/en/features.sessions.php
you can retrive data from the database like this
//start connection
$connect = mysql_connect(DB_SERVER,DB_USER,DB_PASSWORD);
if(!$connect){
die("Database connection Error".mysql_error());
}
//select database
$db = mysql_select_db(DB_NAME);
if(!$db){
die("Database selection Error".mysql_error());
}
//get data
$login = mysql_query("SELECT * FROM TABLENAME where user_id={$_SESSION['user_id']}");
$login_data = mysql_fetch_array($login);
now $login_data array has the user details which you can point to form text field values..
the $_session['user_id']=$login_data['user_id'] value has to be assigned earlier which stays in the $_SESSION global variable through out the session
using mysql as database. I got this code from the previous answers to the same question:
session_start()):
if (isset($_SESSION['loggedin']) && $_SESSION['loggedin'] == true) {
echo "Welcome to the member's area, " . $_SESSION['username'] . "!";
} else {
echo "Please log in first to see this page.";
}
Could you please explain what is: $_SESSION['loggedin'] .
Where could I define it? the loggedin, please help
http://www.php.net/manual/book.session.php
I hope it will help you ;)
$_SESSION is a super-global array (available anywhere) that store all sessions variables.
session_start(); // begins session
$_SESSION['user_id'] = 99;
So, the loggedin variable is set to true when a user logged in, and then it is stored in the session. Sessions are basically information that are saved on the server.
$_SESSION is simply a persistent container where you can store anything and retrieve it in other requests during the same session. As such, you would have to set $_SESSION['loggedin'] and $_SESSION['username'] at the point where the user has successfully logged in.
You use sessions to store userdata to pass it between all pages that get loaded. You can define it as said by others by using the $_SESSION['sessionname'] var.
I will post a simple script below how to let people login on the website since you wanted to know how to use it:
session_start(); #session start alwas needs to come first
//Lets make sure scriptkiddies stay out
$username = mysql_real_escape_string($_POST['username']);
$password = mysql_real_escape_string($_POST['password']);
//Read the user from the database with there credentials
$query = mysql_query("select id from user where username = $username and password = $password");
//Lets check if there is any match
if(mysql_num_rows($query) > 0)
{
//if there is a match lets make the sessions to let the user login
$_SESSION['loggedin'] = true;
$_SESSION['username'] = $username;
}
This is a simple script how to use a Session for a login system. There are many other ways you can use sessions
After login:
$_SESSION['loggedin'] = true;
That's it.